No, 'nowadays' is an example of informal language.
Yes, nowadays is a proper word, it's an adverb, a word to modify a verb as 'at the present time'. For example:Nowadays we take fewer trips than we used to.
Formal is not a compound word.
These kids, nowadays!
The formal word for sister is "sibling."
No, formal is an adjective, the adverb is formally.
The formal word for grandmother in Portuguese is "avó."
Yes, it is often preferred to use a comma after the word "nowadays" when it is used at the beginning of a sentence to separate it from the rest of the sentence. For example: "Nowadays, people rely heavily on technology."
In history we used to write letters, nowadays we send emails.
what is another word for promise? A vow or an oath
3...
Informal? semi-formal
Formal is an adjective.